The Conch Republic Has Just Banned Coral-Toxic Sunscreens, and So Should You!

coral-toxic sunscreens
A thriving staghorn coral thicket at Bonaire, sharp-nose pufferfish included. 

THE EVIDENCE IS CLEAR: THE MOST COMMON CHEMICALS FOUND IN SUNSCREENS, OXYBENZONE AND OCTINOXATE, are damaging to coral reefs and contribute to coral bleaching. The city of Key West in Florida has just joined the state of Hawaii in voting to ban the sale of coral-toxic sunscreens.

At stake is the health of their fragile reefs and, obviously, their futures as destinations for millions of divers and other tourists. They’d like to see reef-safe sunscreen ingredients restricted to safer alternatives like zinc oxides and titanium oxides.


On the other hand, reef experts in Bonaire, in the southern Caribbean, considered banning the lotions and decided to focus instead on a public awareness campaign. It’s not that they wouldn’t like to see the coral toxic lotions eliminated.

They concluded that barring their sale on the island wouldn’t offset their use by the multitudes of cruise ship tourists who bring the stuff with them. They think their best shot is a campaign to change behavior.


As an isolated, well-populated island group, Hawaii would seem to have a better chance to succeed with a ban. Key West, at the southern tip of the Florida Keys, is more vulnerable to tourists simply bringing in their own lotions.

Which leads us to a hard truth: As divers presumably in favor of fostering coral reef health, diving in places where bans may have limited effectiveness, we need to take responsibility for educating ourselves and changing our behaviors.

Three sunscreens, found hanging around my house. All contain oxybenzone, even the Reef Safe product. Several years old, its label emphasizes that its ingredients are biodegradable. The brand does now sell non-oxybenzone lotions.


If you’re committed to buying and using reef-friendly sunscreen, your best bet is (what else?) to Google something like “non-oxybenzone sunscreens.” Some sunscreens that declare themselves safe for the reef do contain oxybenzone, although they do also offer oxybenzone-free lotions, and are better about saying so.

Read labels carefully. Some ingredients, apparently safe, are close in nomenclature to oxybenzone and octinoxate. Consider that lotions may be safer than aerosol sprays; aerosols may spread the stuff to surrounding surfaces and end up in the water.

It’s relevant to add that the reef-friendly products tend to be a little-bit to a lot-more expensive than the popular lotions you can buy in the drug store.

The Environmental Working Group publishes an annual Guide to Sunscreens, indicating ingredients and other factors. Health magazine and Travel & Leisure magazine both offer shorter lists of reef-safe lotions.


Sunscreen lotions generally work via either of two mechanisms. “Chemical” lotions – those using oxybenzone products – minimize the ability of UV rays to penetrate the skin. “Mineral” or “physical” lotions – zinc oxides and the like – block UV rays.

Oxybenzone and octinoxate are a mainstay of major brands like Banana Boat. They’re present in some 70 percent of sunscreen lotions on the market. Multiple studies have clearly indicated that the chemicals are damaging to corals.

“Mineral” lotions are much safer. Most major brands do offer versions based on zinc oxides and similar ingredients. However, you have to look for them and scrutinize the labels.

coral-toxic sunscreens
When you enter the water, the lotion you put on in dry air is going to wash off your body.


The mechanisms are not entirely clear, but the adverse effects on corals of oxybenzone and octinoxate have been noted since at least 2008, when studies first demonstrated that they slowed coral growth and increased rates of coral bleaching.

The National Park Service suggests that the chemicals can awaken coral viruses that weaken corals and cause them to expel their symbiotic zooxanthellae. The result is coral bleaching. The Environmental Working Group suggests that oxybenzone acts as an endocrine disrupter to cause deformation and by damaging the DNA of coral larvae.


It’s an unfortunate fact that a sunscreen slathered on by a beachgoer, diver or any watersports enthusiast will wash off once in the water. And while the wash-off from one human body may seem inconsequential, the stuff accumulates in the face of large populations. It’s estimated that reefs in Hawaii are exposed to more than 6,000 tons of lotion each year.

Worse, their use tends to be concentrated: some 90 percent of diving and snorkeling tourists focus on 10 percent of the world’s reefs. The most popular destinations are subjected to the highest densities of chemicals.


Not surprisingly, lotion manufacturers and trade association spokesmen object to the bans, arguing that such bans are based on “weak science” and work against skin cancer prevention. For that matter, many dermatologists object as well from the standpoint of skin cancer risks.

And, some researchers argue that zinc oxides and the rest, can also harm corals, although most environmentalists seem to conclude that the alternative ingredients are still preferable.


The Hawaii/Key West bans are not the first in the world. Mexico has banned oxybenzone sunscreens from nature reserves and South Pacific nation of Palau has banned them from its famed Jelly Fish Lake.

Hawaii enacted its ban in July of 2018, Key West in February of 2019. As an island group isolated the in the Pacific, Hawaii has the best shot at having an effect. As a vacation destination for millions of visitors each year, locals sunscreen sales are robust. And, local businesses, including Hawaiian Airlines, have worked to develop public awareness campaigns.

coral-toxic sunscreens
Key West sunset.

Key West, a city at the southern tip of the Florida Keys, has a harder challenge: They may ban the sale within city limits but nothing can stop tourists driving down U.S. 1 from the north bringing their own lotions.

“There are thousands of sunscreens out there and we have one reef,” Key West Mayor Teri Johnston said at the before the 6-1 city council vote.  She called banning sale of oxybenzone/octinoxate lotions within the city “one small thing to protect that.”


A “Sunscreen Awareness Bonaire” conference in the Netherland Antilles in March confronted the problem but concluded that a law banning oxybenzone products would take time to enact and would be difficult to enforce.

And a major problem is the use of oxybenzone-based lotions by cruise ship tourists, not island residents or “stay-over” visitors. Cruise ship passengers are more likely to come with their own lotions (and less likely to purchase them on Bonaire). “Stay-over” visitors from the EU, the study found, are less likely to use oxybenzone-based products.

Instead, conference officials went with an awareness campaign intended to educate and change behavior, both generally and among cruise ship tourists. They’re developing materials.

Note: For information about dealing with sunburn, here’s a link to a useful article on Sunburn Safety: How to Protect Yourself From Skin Damage and Practice Sun Safety provided by Camping

PRINCIPAL SOURCES: Can We Create Sunscreen That Protects Both Humans and Coral Reefs?,” Smithsonian; “‘We have one reef’: Key West bans popular sunscreens to help keep coral alive,” “Hawaii just banned your favorite sunscreen to protect its coral reefs,” Washington Post; “Sunscreen Awareness Project,” BioNews; “Sunscreen Awareness Bonaire;” “Is Your Sunscreen Killing the Coral Reef?,” Ocean Conservancy; “Protect Yourself, Protect the Reef,” National Park Service; “EWG’s Sunscreen Guide,” Environmental Working Group;; Travel & Leisure.